Throughout this application, various publications are referenced by arabic numerals within parentheses. Full citations for these publications may be found at the end of the specification immediately preceding the claims The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art as known to those skilled therein as of the date of the invention described and claimed.
Distinct pathways and stages of cellular differentiation are associated with specific patterns of cell-surface antigen expression. This principle was first established through analysis of normal and malignant cells of hematopoietic origin and has been extended to the neuroectodermal lineage (1-7). The identification of an ordered progression of surface phenotypic changes during normal differentiation has permitted classification of leukemias and lymphomas, melanomas, astrocytomas, and neuroblastomas into subsets that show antigenic similarity to normal cells at distinct stages of hematopoietic or neuroectodermal differentiation (2-4, 6, 7). In contrast to the hematopoietic and neuroectodermal systems, little is known about surface antigenic phenotypes of mesenchymal cells and changes in antigen expression that accompany normal differentiation or malignant transformation of these cells. The present study describes six cell-surface glycoproteins that are differentially expressed during normal development, proliferative activation, or malignant transformation of mesenchymal cells and tissues.